Bard Frédéric, Mazelin Laetitia, Péchoux-Longin Christine, Malhotra Vivek, Jurdic Pierre
UCSD Biological Sciences Division, Cell and Developmental Biology Department, University of California-San Diego, La Jolla, CA 92093-0347, USA.
J Biol Chem. 2003 Nov 21;278(47):46601-6. doi: 10.1074/jbc.M302221200. Epub 2003 Sep 15.
The tyrosine kinase Src is present on the Golgi membranes. Its role, however, in the overall function and organization of the Golgi apparatus is unclear. We have found that in a cell line called SYF, which lacks the three ubiquitous Src-like kinases (Src, Yes, and Fyn), the organization of the Golgi apparatus is perturbed. The Golgi apparatus is composed of collapsed stacks and bloated cisternae in these cells. Expression of an activated form of Src relocated the KDEL receptor (KDEL-R) from the Golgi apparatus to the endoplasmic reticulum. Other Golgi-specific marker proteins were not affected under these conditions. Because of the specific effect of Src on the location of KDEL-R, we tested whether protein transport between ER and the Golgi apparatus involves Src. Transport of Pseudomonas exotoxin, which is transported to the ER by binding to the KDEL-R is accelerated by inhibition or genetic ablation of Src. Protein transport from ER to the Golgi apparatus however, is unaffected by Src deletion or inhibition. We propose that Src has an appreciable role in the organization of the Golgi apparatus, which may be linked to its involvement in protein transport from the Golgi apparatus to the endoplasmic reticulum.
酪氨酸激酶Src存在于高尔基体膜上。然而，其在高尔基体整体功能和组织中的作用尚不清楚。我们发现，在一种名为SYF的细胞系中，该细胞系缺乏三种普遍存在的Src样激酶（Src、Yes和Fyn），高尔基体的组织受到了干扰。在这些细胞中，高尔基体由塌陷的堆叠和肿胀的扁平囊组成。活化形式的Src的表达将KDEL受体（KDEL-R）从高尔基体重新定位到内质网。在这些条件下，其他高尔基体特异性标记蛋白未受影响。由于Src对KDEL-R定位的特定作用，我们测试了内质网和高尔基体之间的蛋白质转运是否涉及Src。通过结合KDEL-R转运到内质网的铜绿假单胞菌外毒素的转运在Src受到抑制或基因敲除时加速。然而，从内质网到高尔基体的蛋白质转运不受Src缺失或抑制的影响。我们提出，Src在高尔基体的组织中具有重要作用，这可能与其参与从高尔基体到内质网的蛋白质转运有关。
